Climate-Specific Life-Cycle Cost Analysis of Different HVAC Systems

Abstract

The buildings sector consumes 41.1% of U.S. primary energy, and HVAC system accounts for the major part of building energy consumption. Each type of building has its occupancy schedule and operation preference, and different climate zones offer a broad range of temperature, humidity, wind and solar conditions. When selecting HVAC systems for a new project, designers and engineers should calculate a proper size of the heating and cooling equipment; owners want to know the initial cost and the life-cycle cost of the different options; contractors also need to have a good understanding of HVAC systems to complete the project with a higher quality. This research involves eQUEST Energy Modeling and Life-Cycle Cost Analysis to compare the energy performance and the overall cost efficiency of different HVAC systems in various climate zones based on a typical educational office building. The selected systems are Variable Air Volume (VAV) Reheat system, Chilled Beam system, Air Source Heat Pump (ASHP) system, and Ground Source Heat Pump (GSHP) system. The four climate zones are Miami (FL), Phoenix (AZ), Seattle (WA) and Spokane (WA). The goal of this research is to illustrate a way of selecting the most suitable HVAC system for a project in the specific climate condition. This will be accomplished by using eQUEST Energy Modeling software and developing Life-Cycle Cost Analysis. The life-cycle cost includes the system capital cost, energy cost, system maintenance and replacement cost over a 20-year of life span. The life-cycle cost analysis provides the Present Value (PV) of annual cost and the life cycle cost, and it compares the accumulated cash flow curves of the sixteen models.